Effect of Surfactants on the Belousov-Zhabotinsky Reaction with Ninhydrin as Organic Substrate

Abstract The effects of sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Brij 35 on the oscillations of the cerium-catalyzed Belousov-Zhabotinsky (B-Z) reaction with ninhydrin as the organic substrate at 30 °C were described by following the change in absorbance of the reaction mixtures at 357 nm. The behavior of the oscillatory parameters was determined: (i) the induction period (IP) increases first and then decreases with increasing the concentration of all used surfactants (ii) the number of oscillations decreases with the SDS concentration, while for Brij 35 and CTAB it remains nearly constant, and (iii) the mean amplitude of the oscillations decreases with increasing concentration of CTAB and SDS, while it varies irregularly with that of Brij 35. The ability of micelles to selectively shield ions and molecules may explain their effect on the oscillation parameters of the studied B-Z system.